Fires, flashbacks and other hazards associated with flammable liquids

Jul 15, 2019 Posted by Walter Ingles

Flammable liquids don’t actually burn, they emit vapours that mix with the air and become flammable at certain temperatures and concentrations. But when managing flammable liquids you have to do more than work out how the chemicals could catch on fire — many flammable liquids are also explosive, volatile, corrosive, toxic and carcinogenic. In this blog we’ll be looking closely at the inherent hazards associated with flammable liquids and how your storage and handling practices can decrease the level of risk.

Physical hazards

It’s fairly obvious that flammable liquids can burn, but in order to fully understand a fire hazard and the potential for danger you need to know (and understand) a chemical’s flammable range, auto-ignition temperatures, volatility and flashpoint. You’ll find all this information on the Safety Data Sheet (SDS).

Fire, flashpoint and flashback

As we mentioned in the first paragraph, flammable liquids don’t burn. It’s the vapours that burn.  And the lowest temperature at which the chemical can evaporate and produce enough vapours to ignite and continue burning is called the liquid’s flashpoint. Flammable liquids are classified according to their ‘flashpoint’ — and in Australia any flammable liquids that have a flashpoint of less than 60°C, are classified as Dangerous Goods. 

IMPORTANT: All Dangerous Goods (including Class 3 Flammable Liquids) have mandatory labelling, transport and storage requirements specified by the Australian Dangerous Goods Code (ADG Code). 

Chemicals with a flashpoint that sits within normal working temperatures present a high fire risk to your business. These chemicals must be isolated from any type of ignition source including naked flames, heat, sparks, and static discharge.

IMPORTANT: When a container of flammable liquids is opened, vapours escape into the air. These flammable vapours are denser than air and can travel for hundreds of metres and still be capable of igniting and burning. When a vapour trail ignites and burns, this is called a ‘flashback’.

Auto-ignition and explosions

Storing flammable liquids in dedicated safety cabinets manufactured in accordance with Australia Standards will help prevent the temperature and concentration of the chemicals from reaching their auto-ignition and explosive range. 

  • Auto-ignition - is the temperature at which the chemical will start to burn and sustain a fire without any ignition source. 
  • Explosive range - is the temperature range (and concentration levels) where the chemical can explode.

Always check the SDS to ascertain flashpoint, auto-ignition temperatures and explosive range — these vary for each and every flammable substance.


Health hazards

Many flammable liquids are also harmful to human health and exposure to the vapours can have both immediate and long-term impacts. For example: these common flammable liquids possess serious health hazards and many have workplace exposure standards:

  • Petrol - skin irritant, carcinogenic, mutagenic. Chronic exposure can damage the heart, liver and kidneys.
  • Diesel - skin irritant, may damage major organs through prolonged or repeated exposure, suspected carcinogen.
  • Methylated spirits - skin and eye irritant, repeated exposure may cause skin dryness or cracking.
  • Mineral Turpentine - skin and eye irritant, harmful if inhaled, may cause respiratory irritation.
  • Acetone - skin and serious eye irritant, causes drowsiness and dizziness, can damage major organs.
  • Kerosene - skin irritant, suspected carcinogen,  repeated exposure affects the nervous system. 
  • Benzene - toxic, skin and serious eye irritant, carcinogenic, mutagenic, prolonged exposure to fumes can lead to serious health issues.

It’s essential to carry out a proper risk assessment and consider the way the chemicals are being handled and stored. Your assessment should also factor in exposure times, concentration levels and ventilation.


Environmental hazards

We all want to live in a clean and safe world, and you should also consider the way flammable liquids will impact the environment. Failing to do so may also place you in violation of EPA requirements. 

Flammable liquids can harm the environment in the following ways:

  • Aquatic life - many flammable liquids are toxic to aquatic life, creating long-term adverse effects in the aquatic environment. These chemicals must be prevented from entering drains and sewers.
  • Drinking water - some flammable liquids are hazardous to drinking water even if small quantities leak into the ground. You’ll need measures to prevent the chemicals from reaching ground water, sewerage systems and water courses.
  • Carcinogenic emissions - some flammable liquids create carcinogenic emissions and waste. This is harmful to workers in the immediate area but you should also consider how emissions could impact the local community and natural environment.

IMPORTANT: Always check Section 11. Toxicological information and Section 12. Ecological Information on the SDS. 

Storage and spill containment

Proper storage is key to minimising the adverse impacts of flammable liquids. Safety cabinets, dedicated chemical stores, spill bunds and closed decanting stations are effective ways to:

  • Isolate chemicals from workers, traffic and the general public.
  • Prevent unauthorised people from accessing hazardous chemicals.
  • Segregate flammable liquids from ignition sources and incompatible substances.
  • Contain leaks and spills, enabling safe removal and disposal of liquid waste.
  • Prevent liquid chemicals from entering drains and waterways.

Next steps

Now you have a better understanding of the ways that flammable liquids can cause harm at your workplace we suggest downloading our free eBook Essential Considerations When Storing Flammable Liquids Indoors. In the book we go into more detail about how to determine the level of risk that the chemicals are creating at the workplace and then how to choose a suitable flammable liquids cabinet. Download and read it today, it’s the next step in chemical safety.

Essential Considerations when Storing Flammable Liquids Indoors download Free eBook

Walter Ingles

Walter Ingles Compliance Specialist

Walter is STOREMASTA’s Dangerous Goods Adviser. He loves helping businesses reduce the risk that Dangerous Goods pose upon their employees, property and the environment through safe and compliant dangerous goods storage solutions.

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